Vaisala RVP900 - Defining RVP901 IFDR Input A;D Saturation Levels; RVP901 IFDR Inputs; Table 19 RVP901 IFDR Input Options

4.2.6 RVP901 IFDR Inputs
All RVP901 IFDR inputs are on SMA connectors. The IF signal input is made immediately
after the STALO mixing/sideband filtering step of the receiver, where a traditional log
receiver would normally be installed. The required signal level for both the IF signal and
burst is +8 dBm for the strongest expected input signal.
You can use a
fixed attenuator or IF amplifier to adjust the signal level to be in this range.
The maximum signal level is 20 dBm.
Table 19 RVP901 IFDR Input Options
Input Description
IF signals Four A/D converters are used for received waveforms.
Single polarization radars receive on ADC-A input.
In dual-polarization radars:
• ADC-A is for the primary polarization (usually H).
• ADC-B for the secondary polarization (usually V).
IF signals
(wide dynamic range)
Channels ADC-A and ADC-C are for the H channel:
• ADC-A is the high gain channel.
• ADC-C is the low gain channel.
Channels ADC-B and ADC-D are for the V channel:
• ADC-B is the high gain channel.
• ADC-D is the low gain channel.
IF burst pulse sample for
magnetron
IF COHO for Klystron
Received over ADC-E.
Optional reference clock Used for system synchronization in Klystron systems. The COHO can be input.
Magnetron systems do not require this signal.
Trigger input or output Available on two 5 V 50 Ω driver/receivers.
Digitizing is performed for both the IF signal and burst/COHO channels from a user-
selectable range of 50 ... 100 MHz at 16-bit resolution to sub-nanosecond accuracy. This
provides 92 ... 105 dB of dynamic range (depending on pulse width) without using complex
AGC, dual A/D ranging, or down mixing to a lower IF frequency. Each A/D converters is time
synced within 1 nanosecond to ensure sampling in multiple channels is of the nearly
equivalent targets.
RVP900 provides AFC support for tuning the STALO of a magnetron system. Alternatively,
the magnetron can be tuned by a motorized tuning circuit controlled by RVP900.
4.2.7
Defining RVP901 IFDR Input A/D Saturation Levels
Two analog signals must be supplied to the RVP901 IFDR:
• IF receiver signal
• IF Tx Sample (Burst Pulse) for magnetron, or COHO reference for klystron
RVP900 User Guide M211322EN-J
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